Furthermore, the observation that SPARC-deficient autochthonous urothelial cancers and in syngeneic tumors growing in SP−/− mice exhibited increased vascularity macroscopically with the increased mean vascular density and area (number and size of blood vessels) strongly implicates a direct effect of host and/or tumor SPARC on endothelial cells in the multistep cascade of tumor angiogenesis and vasculogenesis. Here, SPARC is linked to neoplasm.